Your search found 14 records
1 Tischbein, B.. 1997. Betrieb und unterhaltung als grundlagen für die planung von schwerkraftbewässerungssystemen. [Operation and maintenance as fundamentals related to the planning of gravity irrigation systems]. Journal of Applied Irrigation Science; Zeitschrift für Bewässerungswirtschaft, 32(1):43-63.
(Location: IWMI-HQ Call no: P 4541 Record No: H021282)
2 Derib, S. D.; Descheemaeker, Katrien; Haileslassie, A.; Amede, Tilahun; Tischbein, B.. 2010. Water productivity as affected by water management in a small-scale irrigation scheme in the Blue Nile basin, Ethiopia [Abstract only]. Paper presented at the Annual Tropical and Subtropical Agricultural and Natural Resource Management (Tropentag) Conference on World Food System - a contribution from Europe, Thematic scientific session on water management, Zurich, Switzerland, 14 -16 September 2010. 1p.
Water productivity ; Irrigation systems ; Water use ; Irrigated farming ; Land productivity ; Plant production / Ethiopia / Blue Nile basin
(Location: IWMI HQ Call no: e-copy only Record No: H043611)
(0.09 MB)
3 Akhtar, F.; Tischbein, B.; Awan, Usman Khalid. 2013. Optimizing deficit irrigation scheduling under shallow groundwater conditions in lower reaches of Amu Darya River Basin. Water Resources Management, 27(8):3165-3178. [doi: https://doi.org/10.1007/s11269-013-0341-0]
Irrigation scheduling ; Water scarcity ; River basins ; Irrigated farming ; Irrigation water ; Groundwater table ; Water supply ; Crop yield ; Cotton ; Models ; Evapotranspiration / Central Asia / Uzbekistan / Khorezm Region / Amu Darya River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H045846)
(0.23 MB)
Water demand for irrigated agriculture is increasing against limited availability of fresh water resources in the lower reaches of the Amu Darya River e.g., Khorezm region of Uzbekistan. Future scenarios predict that Khorezm region will receive fewer water supplies due to climate change, transboundary conflicts and hence farmers have to achieve their yield targets with less water. We conducted a study and used AquaCrop model to develop the optimum and deficit irrigation schedule under shallow groundwater conditions (1.0–1.2 m) in the study region. Cotton being a strategic crop in the region was used for simulations. Capillary rise substantially contributes to crop-water requirements and is the key characteristic of the regional soils. However, AquaCrop does not simulate capillary rise contribution, thereby HYDRUS-1D model was used in this study for the quantification of capillary rise contribution. Alongside optimal irrigation schedule for cotton, deficit strategies were also derived in two ways: proportional reduction from each irrigation event (scenario-A) throughout the growth period as well as reduced water supply at specific crop growth stages (scenario-B). For scenario-A, 20, 40, 50 and 60 % of optimal water was deducted from each irrigation quota whereas for scenario-B irrigation events were knocked out at different crop growth stages (stage 1(emergence), stage 2 (vegetative), stage 3 (flowering) and stage 4 (yield formation and ripening)). For scenario-A, 0, 14, 30 and 48 % of yield reduction was observed respectively. During stress at the late crop development stage, a reduced water supply of 12 % resulted in a yield increase of 8 %. Conversely, during stress at the earlier crop development stage, yield loss was 17–18 %. During water stress at the late ripening stage, no yield loss was observed. Results of this study provide guidelines for policy makers to adopt irrigation schedule depending upon availability of irrigation water.
4 Awan, Usman Khalid; Tischbein, B.; Martius, C. 2013. Combining hydrological modeling and GIS approaches to determine the spatial distribution of groundwater recharge in an arid irrigation scheme. Irrigation Science, 31(4):793-806. [doi: https://doi.org/10.1007/s00271-012-0362-0]
Groundwater recharge ; Water balance ; Models ; GIS ; Remote sensing ; Irrigation schemes ; Irrigation efficiency ; Water user associations ; Cropping patterns ; Evapotranspiration / Uzbekistan
(Location: IWMI HQ Call no: PER Record No: H045847)
(0.48 MB)
Accurate quantification of the rate of groundwater (GW) recharge, a pre-requisite for the sustainable management of GW resources, needs to capture complex processes, such as the upward flow of water under shallow GW conditions, which are often disregarded when estimating recharge at a larger scale. This paper provides (1) a method to determine GW recharge at the field level, (2) a consequent procedure for up-scaling these findings from field to irrigation scheme level and (3) an assessment of the impacts of improved irrigation efficiency on the rate of GW recharge. The study is based on field data from the 2007 growing season in a Water Users Association (WUA Shomakhulum) in Khorezm district of Uzbekistan, Central Asia, an arid region that is characterized by a predominance of cotton, wheat and rice under irrigation. Previous qualitative studies in the region reported irrigation water supplies far above the crop water requirements, which cause GW recharge. A field water balance model was adapted to the local irrigation scheme; recharge was considered to be a fraction of the irrigation water losses, determined as the difference between net and gross irrigation requirements. Capillary rise contribution from shallow GW levels was determined with the HYDRUS-1D model. Six hydrological response units (HRUs) were created based on GW levels and soil texture using GIS and remote sensing techniques. Recharge calculated at the field level was up-scaled first to these HRUs and then to the whole WUA. To quantify the impact of improved irrigation efficiency on recharge rates, four improved irrigation efficiency scenarios were developed. The area under cotton had the second highest recharge (895 mm) in the peak irrigation period, after rice with 2,514 mm. But with a low area share of rice in the WUA of <1 %, rice impacted the total recharge only marginally. Due to the higher recharge rates of cotton, which is grown on about 40 % of the cropped area, HRUs with a higher share of cotton showed higher recharge (9.6 mm day-1 during August) than those with a lower share of cotton (4.4 mm day-1). The high recharge rates in the cotton fields were caused by its water requirements and the special treatment given to this crop by water management planners due to its strategic importance in the country. The scenario simulations showed that seasonal recharge under improved irrigation efficiency could potentially be reduced from 4 mm day-1 (business-as-usual scenario) to 1.4 mm day-1 (scenario with maximum achievable efficiency). The combination of field-level modeling/monitoring and GIS approaches improved recharge estimates because spatial variability was accounted for, which can assist water managers to assess the impact of improved irrigation efficiencies on groundwater recharge. This impact assessment enables managers to identify options for a recharge policy, which is an important component of integrated management of surface and groundwater resources.
5 Tischbein, B.; Manschadi, A. M.; Conrad, C.; Hornidge, A.-K.; Bhaduri, A.; Ul Hassan, M.; Lamers, J. P. A.; Awan, Usman Khalid; Vlek, P. L. G. 2013. Adapting to water scarcity: constraints and opportunities for improving irrigation management in Khorezm, Uzbekistan. Water Science and Technology: Water Supply, 13(2):337-348. [doi: https://doi.org/10.2166/ws.2013.028]
Water management ; Water scarcity ; Surface water ; Groundwater resources ; Irrigation management ; Irrigation scheduling ; River basins ; Rice ; Salinity control ; Soil water ; Soil moisture ; Vegetation ; Institutions / Uzbekistan / Khorezm
(Location: IWMI HQ Call no: e-copy only Record No: H045861)
(0.36 MB)
Like many irrigation schemes in Central Asia, the one in Khorezm faces a two-fold challenge: on the one side, the severe problems inherited from the past need to be remedied and on the other side, the rising supply–demand gap driven by sharpening competition for water and climate change must be dealt with. Located in the lower part of the Amu Darya basin, Khorezm irrigation and drainage scheme is particularly vulnerable to supply–demand gaps. Promising solutions towards adaptation comprise modified strategies of land and water use towards higher efficiency and flexibility in combination with measures to lessen the constraints of the system itself, which was initially designed for the management of a few, large and uniform production units and not for many diverse and small units. Solutions consist of flexible, modeling-based approaches, re-arranging institutional settings and establishing economic incentive systems. Flexible modeling allows an integrated use of surface and groundwater resources avoiding or minimizing the impact of water stress on yield. Institutional settings strengthen the position of water users via improved participation and transparency of processes in Water Consumers Associations (WCAs). Economic measures support sustainable resource use strategies and improve the functioning of WCAs. The findings could be extrapolated to other regions of Central Asia with similar conditions and challenges.
6 Awan, U. K.; Tischbein, B.; Martius, C. 2015. Simulating groundwater dynamics using feflow-3D groundwater model under complex irrigation and drainage network of dryland ecosystems of Central Asia. Irrigation and Drainage, 64(2):283-296. [doi: https://doi.org/10.1002/ird.1897]
Groundwater recharge ; Surface water ; Water levels ; Hydrology ; Water balance ; Simulation models ; Drainage systems ; Irrigation efficiency ; Water user associations ; Arid zones ; Ecosystems / Central Asia / Uzbekistan / Khorezm Region
(Location: IWMI HQ Call no: e-copy only Record No: H047442)
(2.19 MB)
Surface and groundwater resources are often conjunctively used to cope with water scarcity in irrigated agriculture. Farmers in the dryland ecosystems of central Asia also utilize shallow groundwater in addition to surface water withdrawn from rivers. This study modelled groundwater dynamics in an irrigation and drainage network in Khorezm region, Uzbekistan. The system, characterized by a vast, unlined channel network used to convey water mainly for flood irrigation and an open drainage system, is typical of Central Asian irrigated areas. Groundwater levels in the region are shallow—this contributes to crop water requirements but threatens crop production through secondary salinization. High losses during irrigation in fields and through the irrigation network are the main causes of these shallow groundwater levels. The main objective of this study was thus to simulate groundwater levels under improved irrigation efficiency scenarios. The FEFLOW-3D model, applied in a case study to the water users’ association (WUA) of Shomakhulum in south-west Khorezm, was used to quantify the impact of improved irrigation efficiency scenarios on groundwater dynamics. The modelled scenarios were: current irrigation efficiency (S-A, our baseline), improved conveyance efficiency (S-B), increased field application efficiency (S-C), and improved conveyance and application efficiency (S-D). Recharge rates were separately determined for six hydrological response units (differing in groundwater level and soil type) and introduced into the FEFLOW-3D model. After successful model calibration (R2 = 0.94) and validation (R2 = 0.93), the simulations showed that improving irrigation efficiency under existing agro-hydroclimatic conditions would lower groundwater levels from the baseline scenario (S-A) in August (the peak irrigation period) on average by 12 cm in S-B, 38 cm in S-C and 44 cm in S-D. Any interventions which would improve irrigation efficiency will lower the groundwater levels and hence policy makers should consider them and formulate the policy accordingly.
7 Bekchanov, Maksud; Lamers, J. P. A.; Bhaduri, A.; Lenzen, M.; Tischbein, B.. 2016. Input-output model-based water footprint indicators to support IWRM in the irrigated drylands of Uzbekistan, Central Asia. In Borchardt, D.; Bogardi, J. J.; Ibisch, R. B. (Eds.). Integrated water resources management: concept, research and implementation. Cham, Switzerland: Springer. pp.147-168.
Water footprint ; Water use efficiency ; Water scarcity ; Water demand ; Water supply ; Water resources ; Water management ; Indicators ; Irrigated farming ; Agriculture ; Arid zones ; Supply chain ; Economic sectors ; Economic development ; Crop production ; Fruit ; Vegetables ; Cotton ; Rice ; Empowerment / Central Asia / Uzbekistan
(Location: IWMI HQ Call no: e-copy only Record No: H047543)
(0.52 MB)
Water scarcity due to increasing water demand triggered by population growth and irrigation expansion versus a limited and increasingly variable water supply as a consequence of climate change is presently one of the global challenges. This is exemplified in Uzbekistan, Central Asia, where irrigated agriculture is the primary source of the livelihoods of the rural population that makes more than 60 % of all inhabitants. Yet, socio-economic and ecological challenges keep growing, also due to the inefficient management of water resources. Therefore, options to increase water use efficiency were analyzed while considering the entire supply chain of products including the production, processing, consumption and trade stages and processes. These options were analyzed through an elaborated environmentally extended input-output model. The options examined throughout the entire supply chain included: (i) implementing advanced field-level water saving technologies, (ii) increasing crop diversity through expanding fruits and vegetables production and reducing the area of current dominant crops (cotton and paddy rice in downstream), (iii) fostering the further development of less-water demanding agricultural processing industries, (iv) upgrading production value chains by expanding the production of the commodities with higher values added, (v) reducing production and consumption losses, and (vi) diversifying exports by replacing the current cotton fiber exports with cotton commodities of higher values added. The findings may spur decision-makers to formulating strategic priorities at national level and coordinating water uses considering comprehensively technical, economic and ecological aspects along the entire supply chain, which is a key element of IWRM concepts. However, it is argued that increasing water use efficiency through technological and economic transformation reforms necessitates the empowerment of water users, raising their awareness for, and providing the institutional and market infrastructure, which is in-line with IWRM principles as well.
8 Kumar, N.; Tischbein, B.; Kusche, J.; Laux, P.; Beg, M. K.; Bogardi, J. J. 2017. Impact of climate change on water resources of upper Kharun catchment in Chhattisgarh, India. Journal of Hydrology: Regional Studies, 13:189-207. [doi: https://doi.org/10.1016/j.ejrh.2017.07.008]
Climate change ; Forecasting ; Water resources ; Water balance ; Catchment areas ; Hydrology ; Models ; Groundwater ; Precipitation ; Rainfall-runoff relationships ; Temperature ; Surface runoff ; Discharges ; Percolation ; Land use ; Soils / India / Chhattisgarh / Upper Kharun Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H048326)
http://www.sciencedirect.com/science/article/pii/S221458181630177X/pdfft?md5=b3f01d282a63aa0e5c3b17f5f7e21645&pid=1-s2.0-S221458181630177X-main.pdf
https://vlibrary.iwmi.org/pdf/H048326.pdf
https://vlibrary.iwmi.org/pdf/H048326.pdf
(1.78 MB) (1.78 MB)
Study region: The Upper Kharun Catchment (UKC) is one of the most important, economically sound and highly populated watersheds of Chhattisgarh state in India. The inhabitants strongly depend on monsoon and are severely prone to water stress.
Study focus: This research aims to assess the impact of climate change on water balance components.
New hydrological insights for the region: The station-level bias-corrected PRECIS (Providing REgional Climates for Impact Studies) projections generally show increasing trends for annual rainfall and temperature. Hydrological simulations, performed by SWAT (Soil and Water Assessment Tool), indicate over-proportional runoff-rainfall and under-proportional percolationrainfall relationships. Simulated annual discharge for 2020s will decrease by 2.9% on average (with a decrease of 25.9% for q1 to an increase by 23.6% for q14); for 2050s an average increase by 12.4% (17.6% decrease for q1 to 39.4% increase for q0); for 2080s an average increase of 39.5% (16.3% increase for q1 to an increase of 63.7% for q0). Respective ranges on percolation: for 2020s an average decrease by 0.8% (12.8% decrease for q1 to an increase of 8.7% for q14); for 2050s an average increase by 2.5% (10.3% decrease for q1 to 15.4% increase for q0); for 2080s an average increase by 7.5% (0.3% decrease for q1 to 13.7% increase for q0). These over-and under-proportional relationships indicate future enhancement of floods and question sufficiency of groundwater recharge.
Study focus: This research aims to assess the impact of climate change on water balance components.
New hydrological insights for the region: The station-level bias-corrected PRECIS (Providing REgional Climates for Impact Studies) projections generally show increasing trends for annual rainfall and temperature. Hydrological simulations, performed by SWAT (Soil and Water Assessment Tool), indicate over-proportional runoff-rainfall and under-proportional percolationrainfall relationships. Simulated annual discharge for 2020s will decrease by 2.9% on average (with a decrease of 25.9% for q1 to an increase by 23.6% for q14); for 2050s an average increase by 12.4% (17.6% decrease for q1 to 39.4% increase for q0); for 2080s an average increase of 39.5% (16.3% increase for q1 to an increase of 63.7% for q0). Respective ranges on percolation: for 2020s an average decrease by 0.8% (12.8% decrease for q1 to an increase of 8.7% for q14); for 2050s an average increase by 2.5% (10.3% decrease for q1 to 15.4% increase for q0); for 2080s an average increase by 7.5% (0.3% decrease for q1 to 13.7% increase for q0). These over-and under-proportional relationships indicate future enhancement of floods and question sufficiency of groundwater recharge.
9 Kumar, N.; Tischbein, B.; Beg, M. K.; Bogardi, J. J. 2018. Spatio-temporal analysis of irrigation infrastructure development and long-term changes in irrigated areas in upper Kharun Catchment, Chhattisgarh, India. Agricultural Water Management, 197:158-169. [doi: https://doi.org/10.1016/j.agwat.2017.11.022]
Irrigation systems ; Irrigation canals ; Infrastructure ; Groundwater irrigation ; Irrigation water ; Irrigated land ; Cropping patterns ; Water demand ; Spatial planning ; Mapping ; Satellite imagery ; Villages ; Catchment areas / India / Chhattisgarh / Upper Kharun Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H048525)
(4.39 MB)
The Upper Kharun Catchment (UKC), which is part of the new State Chhattisgarh formed in 2000, features considerable population growth, expansion of urban areas and dynamic changes in irrigation infrastructure as well as irrigation practices (spatial extension, temporal intensification, increasing use of groundwater as source) for meeting the increasing food demand. Water intensive rice is the major crop of the area. UKC has a comprehensive canal irrigation system which provides the link to water supply from reservoirs fed from areas outside the UKC. However, water provision for irrigation via the canal system for irrigation is restricted to only post-monsoon season. As a consequence, groundwater remains the only source of irrigation water in summer and winter seasons. Improved electricity facilities and subsidy on groundwater pumping have triggered an enormous increase in groundwater withdrawals. Remote sensing satellite images along with ground observed data were used in this study to spatially identify the areas with canal and groundwater irrigation. Results reveal that in 2011, around 50% of the area of the UKC benefits from canal irrigation, whereas 29.8% area is irrigated by groundwater. Around 103 villages in the UKC have no canal infrastructures. 216 villages in UKC are considered as ‘hotspot areas’ because of high groundwater withdrawal (irrigated area exceeding 75 ha per village), There has been threefold increase in groundwater irrigated area in UKC between 1991 and 2011. The upward trend of groundwater use indicates an alarming situation towards over-exploitation and creates the need to provide and analyze data on the use of groundwater resources in the area in order to detect past and to estimate future trends referring to groundwater withdrawals. These data are a prerequisite for enabling careful and foresightful management of groundwater resources especially at spatially identified hotspot areas towards ensuring sustainable management of this resource.
10 Sekyi-Annan, E.; Tischbein, B.; Diekkruger, B.; Khamzina, A. 2018. Performance evaluation of reservoir-based irrigation schemes in the upper east region of Ghana. Agricultural Water Management, 202:134-145. [doi: https://doi.org/10.1016/j.agwat.2018.02.023]
Irrigation schemes ; Performance evaluation ; Reservoir storage ; Water users ; Water demand ; Crop yield ; Water availability ; Soil moisture ; Seepage loss ; Transpiration / Ghana / Vea Irrigation Scheme / Bongo Irrigation Scheme
(Location: IWMI HQ Call no: e-copy only Record No: H048699)
(1.63 MB)
The design of relevant adaptation strategies for water users in irrigation schemes in the drylands of Sub-Saharan Africa requires up-to-date information about the current performance of these schemes in view of rapid changes in climate and land use, population growth, and competing water demands. Previous assessments focused primarily on field-level crop irrigation; however, information on the performance of schemes as a whole and considering multiple water users remains scarce. We examined two (one small- and one medium-scale) irrigation schemes shared by multiple users in the Upper East region of Ghana, including the water reservoir, water conveyance and distribution network, cropping fields, and the management entity. Multi-level performance indicators with relevance to water delivery and utilization as well as to agricultural production during two consecutive dry seasons were used. Technical factors, such as underutilized reservoir storage capacity and deteriorated conditions of water delivery infrastructure, strongly undermined the performance. In particular, the medium-scale irrigation scheme utilized less than 40% of total storage, whereas the small-scale scheme utilized about 70% of the storage. An examination of field-level water management practices suggests that an application efficiency of 58–68% is achievable in both schemes by improving the irrigation scheduling of the major crops. Overall system efficiency can be increased from 50% to 68% by reducing water conveyance network losses and by eliminating over-irrigation of fields. A holistic approach considering all competing water demands is needed for the performance evaluation of reservoir-based irrigation schemes in drylands.
11 Akhtar, F.; Nawaz, R. A.; Hafeez, Mohsin; Awan, Usman Khalid; Borgemeister, C.; Tischbein, B.. 2022. Evaluation of GRACE derived groundwater storage changes in different agro-ecological zones of the Indus Basin. Journal of Hydrology, 605:127369. [doi: https://doi.org/10.1016/j.jhydrol.2021.127369]
Groundwater depletion ; Water storage ; Agroecological zones ; River basins ; Water extraction ; Aquifers ; Precipitation ; Trends ; Satellite observation / Pakistan / Afghanistan / Indus Basin / Kabul River Basin / Lower Bari Doab Canal
(Location: IWMI HQ Call no: e-copy only Record No: H050895)
(4.45 MB)
The Gravity Recovery and Climate Experiment (GRACE) has recently been identified as a useful tool for monitoring changes in groundwater storage (GWS), especially in areas with sparse groundwater monitoring networks. However, GRACE’s performance has not been evaluated in the highly heterogeneous Indus Basin (IB) to date. The objective of this study was thus (i) to evaluate GRACE’s performance in two distinctively different agroecological zones of the IB, and (ii) to quantify the trend of groundwater abstraction over 15 years (i.e., from 2002 to 2017). To capture this heterogeneity at the IB, the two different agro-ecological zones were selected: i) the Kabul River Basin (KRB), Afghanistan, and ii) the Lower Bari Doab Canal (LBDC) command area in Pakistan. The groundwater storage anomalies (GWSA) for both regions were extracted from random pixels. The results show a correlation (R2 ) of 0.46 for LBDC and 0.32 for the KRB, between the GWSA and in-situ measurements. The results further reveal a mean annual depletion in GWSA of - 304.2 ± 749 and - 301 ± 527 mm at the LBDC and the KRB, respectively. Overall, a net GWS depletion during 2002–2017 at the LBDC and KRB was 4.87 and 4.82 m, respectively. The GWSA’s response to precipitation analyzed through cross-correlation shows a lag of 4 and 3 months at the KRB and the LBDC, respectively. The GWSA’s poor correlation with the in-situ measurements particularly in the mountainous region of the KRB is driven by the 4 months lag time unlike in the LBDC (i.e. 3 months); besides, the observations wells are sparse and limited. The complex geomorphology and slope of the landscape also cause discrepancies in the correlation of the in-situ measurements and the GRACE-derived changes in GWS at the two different agroecological zones of the IB. The spatially averaged GWSA in monthly time steps is another reason for the lower correlation between GRACE-based GWSA estimates and point-based in-situ measurements. Therefore, care must be taken while using GRACE’s output in regions with heterogeneous geomorphologic features.
12 Idrissou, M.; Diekkruger, B.; Tischbein, B.; Op de Hipt, F.; Naschen, K.; Pomeon, T.; Yira, Y.; Ibrahim, B. 2022. Modeling the impact of climate and land use/land cover change on water availability in an inland valley catchment in Burkina Faso. Hydrology, 9(1):12. (Special issue: Integrated Effect of Climate and Land Use on Hydrology and Soil Erosion) [doi: https://doi.org/10.3390/hydrology9010012]
Climate change ; Land use change ; Land cover change ; Water availability ; Catchment areas ; Hydrological modelling ; Forecasting ; Precipitation ; Climate variability ; Evapotranspiration ; Water balance ; Farmland ; Vegetation ; Impact assessment ; Uncertainty / West Africa / Burkina Faso / Bankandi-Loffing Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H050874)
(4.07 MB) (4.07 MB)
Water scarcity for smallholder farming in West Africa has led to the shift of cultivation from uplands to inland valleys. This study investigates the impacts of climate and land use/land cover (LULC) change on water resources in an intensively instrumented inland valley catchment in Southwestern Burkina Faso. An ensemble of five regional climate models (RCMs) and two climate scenarios (RCP 4.5 and RCP 8.5) was utilized to drive a physically-based hydrological model WaSiM after calibration and validation. The impact of climate change was quantified by comparing the projected period (2021–2050) and a reference period (1971–2000). The result showed a large uncertainty in the future change of runoff between the RCMs. Three models projected an increase in the total runoff from +12% to +95%, whereas two models predicted a decrease from -44% to -24%. Surface runoff was projected to show the highest relative change compared to the other runoff components. The projected LULC 2019, 2025, and 2030 were estimated based on historical LULC change (1990–2013) using the Land Change Modeler (LCM). A gradual conversion of savanna to cropland was shown, with annual rates rom 1 to 3.3%. WaSiM was used to simulate a gradual increase in runoff with time caused by this land use change. The combined climate and land use change was estimated using LULC-2013 in the reference period and LULC-2030 as future land use. The results suggest that land use change exacerbates the increase in total runoff. The increase in runoff was found to be +158% compared to the reference period but only +52% without land use change impacts. This stresses the fact that land use change impact is not negligible in this area, and climate change impact assessments without land use change analysis might be misleading. The results of this study can be used as input to water management models in order to derive strategies to cope with present and future water scarcities for smallholder farming in the investigated area.
13 Akhtar, F.; Awan, Usman Khalid; Borgemeister, C.; Tischbein, B.. 2021. Coupling remote sensing and hydrological model for evaluating the impacts of climate change on streamflow in data-scarce environment. Sustainability, 13(24):14025. [doi: https://doi.org/10.3390/su132414025]
Climate change ; Remote sensing ; Hydrological modelling ; Forecasting ; River basins ; Stream flow ; Water resources ; Precipitation ; Land use ; Land cover ; Soil types ; Calibration / Afghanistan / Kabul River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050783)
(6.38 MB) (6.38 MB)
The Kabul River Basin (KRB) in Afghanistan is densely inhabited and heterogenic. The basin’s water resources are limited, and climate change is anticipated to worsen this problem. Unfortunately, there is a scarcity of data to measure the impacts of climate change on the KRB’s current water resources. The objective of the current study is to introduce a methodology that couples remote sensing and the Soil and Water Assessment Tool (SWAT) for simulating the impact of climate change on the existing water resources of the KRB. Most of the biophysical parameters required for the SWAT model were derived from remote sensing-based algorithms. The SUFI-2 technique was used for calibrating and validating the SWAT model with streamflow data. The stream-gauge stations for monitoring the streamflow are not only sparse, but the streamflow data are also scarce and limited. Therefore, we selected only the stations that are properly being monitored. During the calibration period, the coefficient of determination (R2) and Nash–Sutcliffe Efficiency (NSE) were 0.75–0.86 and 0.62–0.81, respectively. During the validation period (2011–2013), the NSE and R2 values were 0.52–0.73 and 0.65–0.86, respectively. The validated SWAT model was then used to evaluate the potential impacts of climate change on streamflow. Regional Climate Model (RegCM4-4) was used to extract the data for the climate change scenarios (RCP 4.5 and 8.5) from the CORDEX domain. The results show that streamflow in most tributaries of the KRB would decrease by a maximum of 5% and 8.5% under the RCP 4.5 and 8.5 scenarios, respectively. However, streamflow for the Nawabad tributary would increase by 2.4% and 3.3% under the RCP 4.5 and 8.5 scenarios, respectively. To mitigate the impact of climate change on reduced/increased surface water availability, the SWAT model, when combined with remote sensing data, can be an effective tool to support the sustainable management and strategic planning of water resources. Furthermore, the methodological approach used in this study can be applied in any of the data-scarce regions around the world.
14 Akhtar, F.; Borgemeister, C.; Tischbein, B.; Awan, Usman Khalid. 2022. Metrics assessment and streamflow modeling under changing climate in a data-scarce heterogeneous region: a case study of the Kabul River Basin. Water, 14(11):1697. [doi: https://doi.org/10.3390/w14111697]
Stream flow ; Modelling ; Climate change ; River basins ; Case studies ; Watersheds ; Soil water content ; Land use ; Land cover ; Temperature ; Parameters / Afghanistan / Kabul River Basin / Alingar Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H051380)
https://www.mdpi.com/2073-4441/14/11/1697/pdf?version=1653561387
https://vlibrary.iwmi.org/pdf/H051380.pdf
https://vlibrary.iwmi.org/pdf/H051380.pdf
(2.75 MB) (2.75 MB)
Due to many uncertainties in hydrological data and modeling, the findings are frequently regarded as unreliable, especially in heterogeneous catchments such as the Kabul River Basin (KRB). Besides, statistical methods to assess the performance of the models have also been called into doubt in several studies. We evaluated the performance of the Soil and Water Assessment Tool (SWAT) model by statistical indicators including the Kling-Gupta efficiency (KGE), Nash–Sutcliffe efficiency (NSE), and the coefficient of determination (R2 ) at single and multi-outlets in the KRB and assessed the streamflow under changing climate scenarios i.e., Representative Concentration Pathways (RCP) 4.5 and 8.5 (2020–2045). Because of the heterogeneous nature of the KRB, NSE and R 2 performed poorly at multi-outlets. However, the KGE, as the basic objective function, fared much better at singleoutlet. We conclude that KGE is the most crucial metric for streamflow evaluation in heterogeneous basins. Similarly, the mean and maximum annual streamflow is projected to decrease by 15.2–15.6% and 17.2–41.8% under the RCP 4.5 and 8.5, respectively.
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